Although widespread support favors prospective planning for altered standards of care during mass casualty events, the literature includes few, if any, accounts of groups that have formally addressed the overarching policy considerations at the state level. We describe the planning process undertaken by public health officials in the Commonwealth of Massachusetts, along with community and academic partners, to explore the issues surrounding altered standards of care in the event of pandemic influenza. Throughout 2006, the Massachusetts Department of Public Health and the Harvard School of Public Health Center for Public Health Preparedness jointly convened a working group comprising ethicists, lawyers, clinicians, and local and state public health officials to consider issues such as allocation of antiviral medications, prioritization of critical care, and state seizure of private assets. Community stakeholders were also engaged in the process through facilitated discussion of case scenarios focused on these and other issues. The objective of this initiative was to establish a framework and some fundamental principles that would subsequently guide the process of establishing specific altered standards of care protocols. The group collectively identified 4 goals and 7 principles to guide the equitable allocation of limited resources and establishment of altered standards of care protocols. Reviewing and analyzing this process to date may serve as a resource for other states. (Disaster Med Public Health Preparedness. 2009;3(Suppl 2):S132–S140)